Using streamflow characteristics to explore permafrost thawing in northern Swedish catchments

Sjöberg, Ylva; Frampton, Andrew; Lyon, SteveW.

Using streamflow characteristics to explore permafrost thawing in northern Swedish catchments | Utilisation des caractéristiques de l’écoulement superficiel pour explorer la fonte du pergélisol sur des bassins versants de la Suède du Nord Uso de las características del flujo de una corriente para explorar el deshielo del permafrost en cuencas suecas nórdicas 利用河川径流特征探讨瑞典北部流域永久冻土的融化 Uso das características de escoamento de cursos de água para exploração do degelo do permafrost em bacias hidrográficas no norte da Suécia

2013

Sjöberg, Ylva | Frampton, Andrew | Lyon, SteveW.

The recent and rapid warming of the Arctic leads to thawing of permafrost, which influences and changes subsurface water-flow systems in such landscapes. This study explores the utility of catchments as “sentinels of change” by considering long-term discharge data from 17 stations on unregulated rivers in northern Sweden and analyzing trends in annual minimum discharge and recession flow characteristics. For the catchments considered, the annual minimum discharge has increased significantly (based on the Mann Kendall test at a 95 % confidence level) in nine of the catchments and decreased significantly in one catchment. Considering changes in recession-flow characteristics, seven catchments showed significant trends consistent with permafrost thawing while two catchments showed significant trends in the opposite direction. These results are mechanistically consistent with generic physically based modeling studies and the geological setting, as the catchments considered span the spatial limit of permafrost extent. This study illuminates the potential for using hydrologic observations to monitor changes in catchment-scale permafrost. Further, this opens the door for research to isolate the mechanisms behind the different trends observed and to gauge their ability to reflect actual permafrost conditions at the catchment scale.

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